ci.ICC1a {irrICC}

Confidence Interval of Intraclass Correlation Coefficient (ICC) under ANOVA Model 1A.

Description

This function computes the lower and upper confidence bounds associated with the ICC under the one-factor ANOVA model where each subject may be rated by a different group of raters.

Usage

ci.ICC1a(ratings, conflev = 0.95)

Arguments

ratings

This is a data frame containing 3 columns or more. The first column contains subject numbers (there could be duplicates if a subject was assigned multiple ratings) and each of the remaining columns is associated with a particular rater and contains its numeric ratings.

conflev

This is the optional confidence level associated with the confidence interval. If not specified, the default value will be 0.95, which is the most commonly-used valuee in the literature.

Value

This function returns a vector containing the lower confidence (lcb) and the upper confidence bound (ucb).

References

Gwet, K.L. (2014): Handbook of Inter-Rater Reliability - 4th ed. chapter 8, section 8.3.1, equations 8.3.1 and 8.3.2. Advanced Analytics, LLC.

Examples

#iccdata3 is a small dataset that comes with the package. Use it as follows:
library(irrICC)
iccdata3 #see what the iccdata3 dataset looks like
ci.ICC1a(iccdata3)